Pain in the Butt, Sacroiliac Pain as Tendinopathy?

I recently finished the 3rd edition Stuart McGill’s “Low Back Disorders.” I’ve followed his work since reading edition 2 and bulk of my back pain treatments are based on, or consistent with it and his more recent research. For those who don’t know, McGill is a Professor of Spine Biomechanics at the University of Waterloo in Canada, for which he focuses entirely on low back pain. Subsequently, more of my back pain blogs reference his research than any other source.

I was wondering what was new in the 3rd and if it were worth buying and reading through. In short, it was both. The basic gist of his treatment hasn’t changed (but there was a lot of additional detail and ideas). Said gist to eliminate back pain is to lessen the injury causing stress from daily activities, while working on exercises (to make the person fit enough) and motor skills (to make them coordinated enough) to better tolerate the rigors of life without reinjury. I 100% endorse those principles.

All the above is all filler, and sets up what I wanted to get too, which was one of the more interesting sections new to the 3rd edition of Low Back Disorders which I have never seen mentioned anywhere else. The observation appears to be anecdotal, but it’s Stuart McGill’s anecdote, which means something, and I also happen to think this observation is often correct. On page 142 he talks about sacroiliac pain (literally pain in the butt) with the following being a few of his quotes:

“Boguk and colleagues (1996) proved that some low back pain is from the sacroiliac joint itself. The following discussion offers other considerations.”

“One possibility worth considering is that the high muscular forces may damage the bony attachments of the corresponding muscle tendons. Such damage has perhaps been wrongfully attributed to alternate mechanisms.”

“It is known that a large portion of the extensor musculature obtains its origin in the SI and posterior superior iliac spine (PSIS) region (Bogduk, 1980). The area of tendon-periosteum attachment area for connective tissue places the connective tissue at high risk of sustaining microfailure, resulting in pain (McGill, 1987).”

“This mechanical explanation may account for local tenderness on palpation associated with many SI syndrome cases.”

My comments:

McGill didn’t use the the word tendinitis, or more accurately the words tendinosis and tendinopathy. However, when he uses the words “microfailure” of the “tendon-periosteum attachment area” of the spine “extensor musculature” at it’s point of “origin in the SI and posterior superior iliac spine” it sure sounds like he’s describing tendinosis, with the resulting pain being tendinopathy of the spine extensor tendons. So far there is zero research describing tendinopathy in this region, but there is no reason I can think of why it couldn’t be. Also thinking about it, gluteus maximus also attaches right there, along the SI joint region as well, so it’s tendinous region could be involved as well, while all this time it’s been blamed on the SI joint or the piriformis muscle (which I have never seen get better stretches either).

The SI joint as a source of motion or pain has long been a source of debate in physical therapy, with studies and arguments pointing for and against for decades. I’ve never been passionately drawn to either side of the argument. However, I have stress tested a lot of SI joints and rarely do I find those tests positive for pain, and if the tests are painful, I think it’s still hard to tell if the SI joint itself is the source. Also I’m skeptical treatments directed at the SI joint reliably decrease that pain. I wouldn’t go so far as to say they never do, but just not often enough to make such treatments worth routinely doing. I’ll add that sometimes when there is debate and no clear answer, it’s because there’s something amiss and it wouldn’t be the first time that tendinopathy reared it’s head in an unbenounced place. Another reason I don’t usually give SI pain special attention is my SI pain patients generally get all the way better with my somewhat standard low back treatment protocol. So thinking about what McGill wrote above, how I treat back pain and how I treat tendinopathy, I have a idea as to the reason why.

That reason is that my treatment protocol for back pain, bares more than a passing resemblance to my treatment for tendinopathy. In short, I’m basically treating for both already. Besides biomechanical and postural counseling, teaching the person with back pain how to better maintain a neutral spine during the day, I have them work to increase basically total body strength and endurance emphasising spine stability and hip mobility, with an exercise program that is generally 3 sets of 15 reps, with easy-medium-hard resistance levels. I have them progressing the weights on the next visit if the person is able to get all three sets without pain and with good technique on the prior treatment. That’s almost identical to how I treat tendinopathy, with an example being tennis elbow (aka shooter’s elbow described here) or coracoidopathy described here. In both cases I try to increase strength and endurance of all the muscles stabilizing the affected area, followed by focused strengthening of the affected muscle/tendon with 3 sets of 15 reps ( also easy-medium-hard resistance levels).

So if a person has tendinopathy of their spine extensor muscles (or gluteus maximus) where they attach on or near the SI joint, that would explain why my back pain type sets and reps, has hitherto resolved those symptoms without me even considering tendinopathy of the area being a possible cause.

Some considerations I’ll be thinking about going forward is that with back pain I endeavor to never have my patients train through pain, however with tendinopathy I try to use a resistance level that causes some pain, noting that pain almost always stays the same/or lessens in spite of increasing weights from set to set. With back pain, for which I might suspect a bulged (nearly bulged) or herniated disc, training through pain usually results in a worsening the person’s condition from one set to the next. Also with tendinopathy I notice people get better faster if they do the exercises every day rather than three times a week and my observation does have empirical support.

So if there is SI region tendinopathy I think it’s probably better to error on the site of caution and not increase resistance levels if there is any pain, which thus far seems to be working well enough. However, if the person has SI region pain, no lumbar or radicular symptoms (leg pain and tingling) I might consider a slightly more aggressive (slightly more specific tendinopathy) type approach. However, I imagine there is a lot of overlap between both conditions, such that if someone has spine extensor tendinopathy, they very likely have some spine disc or ligament issues as well even if they don’t have pain yet, so daily pain free resistance exercise of the spine and hip extensor muscles (with the spine kept neutral throughout) is maybe the safest and best approach.

For the record, I suspect upper back pain and tenderness where the levator scapula muscle attaches to the scapula is sometimes and maybe often be tendinopathy too. Which seems to resolve with my basic neck pain protocol, which like my back pain treatments includes (your guessed it) progressive resistance training with 3 sets of 15 reps (easy-medium-hard).

Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember Spinal Flow Yoga for you or someone you know in the future.

Chad Reilly is a Physical Therapist obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed Yoga Teacher Training at Sampoorna Yoga in Goa, India.

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8 thoughts on “Pain in the Butt, Sacroiliac Pain as Tendinopathy?”

Have you had a chance to read McGill’s “Back Mechanic”? I find myself using this book and “Ultimate Back Fitness and Performance” a little more than his “Low Back Disorders”. I was a little disappointed in his DVD’s, the one I have is a glorified video of some of his continuing education courses. All his work is worthwhile. Too bad he is retiring from academics.

Yeah I actually just finished Back Mechanic a few weeks ago. I really liked how McGill worded some concepts in it, and with it I think I can better explain some ideas to my patients. Plus, it was a good review of what he thinks is most important. I think it’s definitely more accessible than Low Back Disorders for laymen, but that most people aren’t going to read something that detailed either. And yeah, as much as I agree with McGill’s treatment principles, I do tend to incorporate them into more fitness type exercises like in Ultimate Back Fitness or rather some of my favorite weightlifting/bodybuilding exercises, minus the one’s bad for the back, more so than what’s in Low Back Disorders. Heck, now that I use EMS for abdominal strengthening, I don’t use “the big three” that much anymore. I still think the big three are great for a HEP when patients don’t have any equipment, though I almost always use the “modified side bridge” instead of the normal one.

My above blog was getting long, but I was thinking that if you had SI region tendinopathy that you would need higher intensity exercise to remodel those tendons than a bird dog would provide, so standing cable rows, squats, RDLs, etc. with weights would maybe work better. I’m thinking the same thing for greater trochanteric pain syndrome and gluteal tendinopathy, where more aggressive progressive resistance exercise (with the spine still locked in neutral) would better remodel the tendinosis region than big three and clam shell type exercises can deliver. Maybe full on side bridges would, but I notice they can be hard on the shoulders of my patients who often aren’t as fit as the McGill subjects in his books.

As for the DVDs, I guess I liked them all, maybe not the golf one so much, but I agree I get more out of the books. I hadn’t heard about him retiring, but I suppose he’s earned it. I’ve been following some of Jack Callaghan’s stuff regarding standing low back pain in particular. I think they worked out of the same lab at the University of Waterloo. Definitely let me know if you come across anyone else worth reading. I’m on a roll for back pain books, having recently finished Back Pain Revolution and got almost nothing out of it, except I think for a thorough understanding of the holes in the biopsychosocial model. I’ve been meaning to do a blog on that one as well.

hi chad,
it was because of you that i found out about stu mcgill over a month ago. i had been off work for over 2 months back in late february looking at mckenzie physio videos when i decided to see if anyone had anything critical to say about it which led me to your blog where you referenced stu mcgill. i live close to waterloo and my nephew’s wife teaches pharmacy at u of w. i had never heard of the guy and not one of the physios i had ever gone too mentioned him or his work or followed his recovery path. i spent days watching a lot of his videos and listening to other physios interviewing him on their blogs and then ended up buying back mechanic. i emailed him asking whether he could recommend someone he trained or knew that i could see for an assessment.lo and behold i got a reply 30 minutes later from mcgill himself. he’s retired and living up in what we call cottage country. he still examines and treats individuals for $600 cdn dollars a month if anyone is curious but did recommend a former phd student of his who is now a chiropractor.

so thanks a bunch there chad. I wish you practiced around here. i’ve watched a few of your videos. keep up the good work and say hello to walter white for me 😉

That’s a cool story! It’s interesting to me that none of the local physios to you had heard of him. From what I can tell here in the USA, not that many physical therapists are aware of or follow his research either. I’m glad you were able to find help nearby, it seems a lot of people cant.

A number of people were telling me about that article and I have numerous and mixed feelings. It’s timely because my project for this year is to come up with an ideal yoga routine for low back and neck pain. The aim being a sequence of exercise that maintains a neutral spine throughout, improves spine stability, hip mobility, teaches good motor control, etc. Basically a yoga sequence that incorporates all the good that McGill talks about, including (as best as I can) my strength training stuff, while avoiding all the spine flexion/extension and twisting, which admittedly rules out a lot of traditional yoga asanas. Also I still want to preserve various and positive mindfulness aspects of yoga, which seems to be holding up well in the research. In doing so I’ve taken a fair share of yoga classes, read most of the yoga and back pain research, as well as books. So it’s good timing that this paper came out now.

It took us a while to find the above paper, but here it is. They don’t list any of the details about either the yoga program or the physical therapy routine in that paper but here is the teacher training manual that describes the yoga routine reasonably well. We have to go back to their 2014 protocol description to see the details regarding the physical therapy program. Basically it sounded like McKenzie stretches into either flexion or extension (and we all know what I think of McKenzie method) plus some very low intensity and extremely long duration lumbar stabilization exercises. Like 30 reps with 8 second holds. It’s hard for me to imagine anything more boring. That was followed by 30 minutes of aerobic exercise, and no modalities. I couldn’t see that they did anything substantial to strengthen hips nor anything to teach good spine/hip motor control in real life situations. The researchers referred to the pain as non-specific, so overall I got the impression they didn’t have any exposure to McGill’s research. So in short I thought it was a substandard (though fairly standard) yoga routine, followed by a substandard physical therapy routine (not that I think most PT protocols are worth bragging about). So I’m not surprised the results were similar. What they fail to mention is the world news outlets and all the press this paper got was that neither the yoga nor the physical therapy program improved pain very much over that of the education group, who just got a book to read. The book itself being a copyright 1999 hodgepodge of what I think was some good and some bad advice. It definitely wasn’t “Back Mechanic.”

What didn’t make the news was the fact that neither the yoga nor the physical therapy program worked very well. Outcomes for both were better than the education only group, but outcomes weren’t that much better. For example at week 12 the yoga and physical therapy pain scores dropped from 7ish only to a 5ish, while the control group decreased to a 7/10 to a 6, which would make me wonder if any of the routines were worth the effort or if either the yoga or physical therapy programs were better than placebo, and were perhaps just a higher, or more theatrical a placebo.

I have a lot more comments that I’m working on now about the best way to share them, such that they’ll be well received. I’m thinking that’s the tricky part.

This blog is one of my older “legacy” (2017 and older) blogs from my prior physical therapy site. So if the information you find here seems a bit broad for yoga, or is a bit technical, it’s because I wrote it with a slightly different audience in mind. However, I think each blog does showcase my thought process and research base, both of which very much influenced what became Spinal Flow Yoga. Further, given that spine pain has always been a favorite topic of mine, much of the content within the legacy blogs will be directly relevant to Spinal Flow even if a couple times it seems I criticized yoga. In fact that’s why I created Spinal Flow Yoga, to correct what were, and still are, physical problems in modern yoga sequences. Time permitting, I may revisit some of my older blogs and add some content relating them to newer Spinal Flow concepts that aim to cure neck and back pain as well as improve overall health and fitness from the comfort of your own home without the need for equipment. Hopefully that will make more sense out of why this blog is here. Click the X or anywhere outside this box to read on.